U.S. patent number 7,791,869 [Application Number 12/256,764] was granted by the patent office on 2010-09-07 for electronic device including a rotation unit.
This patent grant is currently assigned to Alps Electric Co., Ltd.. Invention is credited to Tsutomu Takeya.
United States Patent |
7,791,869 |
Takeya |
September 7, 2010 |
Electronic device including a rotation unit
Abstract
A rotation unit is supported to a device main body unit so as to
rotate about a rotation supporting point. The rotation unit is
rotated from a closure posture close to the device main body unit
until a rotation limit position at 180 degrees. A magnet is fixed
to the rotation unit at a position away from the rotation
supporting point, and the device main body unit is provided with a
detector capable of distinctly detect magnetic fields in two
directions. When the rotation unit is rotated from the closure
posture at a predetermined angle, a first open detection output is
obtained form the detector and a display unit provided to the
rotation unit is turned ON. The rotation unit is further rotated
and when a second open detection output is obtained from the
detector, the display content of the display unit is switched to be
turned upside down.
Inventors: |
Takeya; Tsutomu (Niigata-ken,
JP) |
Assignee: |
Alps Electric Co., Ltd. (Tokyo,
JP)
|
Family
ID: |
39608687 |
Appl.
No.: |
12/256,764 |
Filed: |
October 23, 2008 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20090052123 A1 |
Feb 26, 2009 |
|
Foreign Application Priority Data
|
|
|
|
|
Jan 11, 2007 [JP] |
|
|
2007-003734 |
Jan 9, 2008 [WO] |
|
|
PCT/JP2008/050104 |
|
Current U.S.
Class: |
361/679.27;
378/95; 340/815.86; 248/176.1 |
Current CPC
Class: |
G01R
33/09 (20130101); G06F 1/1677 (20130101); G01D
5/145 (20130101); G06F 1/1616 (20130101) |
Current International
Class: |
G06F
1/16 (20060101) |
Field of
Search: |
;361/679.27,679.55,679.06,679.21,679.29 ;248/187,176.1,917
;345/175,30,111,173,649,204 ;340/815.62,815.86,319,815.4
;604/22,288.01 ;378/4,19,57,95 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Duong; Hung V
Attorney, Agent or Firm: Brinks Hofer Gilson & Lione
Claims
What is claimed is:
1. An electronic device comprising: a device main body unit; a
rotation unit freely rotatably supported to the device main body
unit; a display unit provided to the rotation unit, the rotation
unit rotating between a closure posture in which the display unit
faces the device main body unit and a display posture in which the
display unit is away from the device main body; a magnet provided
to one of the device main body unit and the rotation unit; and a
detector provided to the other of the device main body unit and the
rotation unit, wherein: diverse magnetic poles of the magnet are
arranged in mutually opposite directions in a surface orthogonal to
a rotation central line of the rotation unit; the detector has a
fixed magnetic layer in which a direction of magnetization is fixed
and a free magnetic layer in which the magnetization is changed due
to external magnetic field and is composed of a magnetoresistance
effect element capable of detecting the direction and intensity of
the external magnetic field on the basis of the direction of the
magnetization of the fixed magnetic layer and the direction of the
magnetization of the free magnetic layer; and the detector detects
an intensity change of the magnetization in one direction output
from the magnet and obtains a first open detection output when the
rotation unit is rotated at a predetermined angle from the closure
posture to the display posture, and the detector detects an
intensity change of the magnetization in the other direction output
from the magnet and obtains a second open detection output when the
rotation unit is further rotated toward the display posture after
the first open detection output is obtained.
2. The electronic device according to claim 1, wherein when the
rotation unit is rotated at an angle above 150 degrees from the
closure posture, the second open detection output is obtained from
the detector.
3. The electronic device according to claim 1, wherein when the
first open detection output is obtained as the rotation unit is
rotated from the closure posture to the display posture, a display
of the display unit is turned ON, and when the second open
detection output is obtained, a display content of the display unit
is switched.
4. The electronic device according to claim 2, wherein when the
first open detection output is obtained as the rotation unit is
rotated from the closure posture to the display posture, a display
of the display unit is turned ON, and when the second open
detection output is obtained, a content displayed on the display
unit is turned upside down to be displayed.
5. The electronic device according to claim 4, wherein an angle and
a direction of the magnet and the detector are set to have a
rotation angle of the rotation unit up to a rotation limit position
of the display posture is reached after the second open detection
output is obtained, smaller than a rotation angle of the rotation
unit from the closure posture up to an angle at which the first
open detection output is obtained.
6. The electronic device according to claim 4, wherein when the
rotation unit is rotated at a predetermined angle from a rotation
limit position of the display posture to the closure posture, a
second closure detection output is obtained, and when the rotation
unit is rotated at a predetermined angle toward the closure posture
after the second closure detection output is obtained, a first
closure detection output is obtained.
7. The electronic device according to claim 6, wherein a rotation
angle of the rotation unit from the rotation limit position up to
an angle at which the second closure detection output is obtained
is larger than a rotation angle of the rotation unit up to the
rotation limit position after the second closure detection output
is obtained.
8. The electronic device according to claim 7, wherein when the
second closure detection output is obtained as the rotation unit is
rotated from the rotation limit position toward the closure
posture, the display content of the display unit is returned to an
original state.
9. The electronic device according to claim 6, wherein a rotation
angle of the rotation unit toward the closure posture after the
first closure detection output is obtained is smaller than a
rotation angle of the rotation unit from the closure posture up to
an angle at which the first closure detection output is
obtained.
10. The electronic device according to claim 9, wherein when the
first closure detection output is obtained as the rotation unit is
rotated toward the closure posture, the display of the display unit
is turned OFF.
11. The electronic device according to claim 1, wherein the
detector includes a detection element adapted to utilize a
magnetoresistance effect.
Description
CLAIM OF PRIORITY
This application claims benefit of the Japanese Patent Application
No. 2007-003734 filed on Jan. 11, 2007, which is hereby
incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic device including a
rotation unit provided with a display unit, the rotation unit being
capable of detecting a rotating angle of the rotation unit by using
a detector capable of detecting a direction and an intensity of
magnetic field.
2. Description of the Related Art
In a book-type personal computer, an in-vehicle display device, or
the like, a rotation unit having a display unit such as a liquid
crystal panel is freely rotatably mounted to a device main body
unit. In an electronic device of this type, a sensor for detecting
a rotation angle of the rotation unit is provided. When a sensor
detects that the rotation unit is rotated up to a predetermined
angle, a display of the display unit is turned ON or turned OFF, or
display content is switched.
Japanese Unexamined Patent Application Publication No. 2002-132385
discloses a note-type personal computer, in which a detection of a
rotation angle of a rotation unit is performed by using an angle
sensor built in a hinge part. Japanese Unexamined Patent
Application Publication No. 10-309996 discloses an in-vehicle
display device having a rotation unit. In this display device, an
angle of the rotation unit is detected on the basis of an encoder
type detection method or a micro switch.
However, when the angle sensor or the encoder is mounted to the
hinge part of the rotation unit, a structure of the hinge part
becomes complicated. Also, each time the rotation unit is rotated,
the mechanical component such as the angle sensor or the encoder
contact or slide, and the life of the angle sensor or the encoder
is unavoidably shortened. In addition, the micro switch needs to be
arranged at the hinge part of the rotation unit, and it is
difficult to find an arrangement space.
SUMMARY OF THE INVENTION
The present invention has been made in order to solve the
above-described problems and provides an electronic device
including a rotation unit provided with a display unit, the
rotation unit being capable of detecting a rotating angle of the
rotation unit by using a non-contact and non-sliding type detector,
in which a setting of a detection timing is also easily
performed.
According to an embodiment of the present invention, there is
provided an electronic device including: a device main body unit; a
rotation unit freely rotatably supported to the device main body
unit; a display unit provided to the rotation unit, the rotation
unit rotating between a closure posture in which the display unit
faces the device main body unit and a display posture in which the
display unit is away from the device main body; a magnet provided
to one of the device main body unit and the rotation unit; and a
detector provided to the other of the device main body unit and the
rotation unit, in which: diverse magnetic poles of the magnet are
arranged in mutually opposite directions in a surface orthogonal to
a rotation central line of the rotation unit; the detector has a
fixed magnetic layer in which a direction of magnetization is fixed
and a free magnetic layer in which the magnetization is changed due
to external magnetic field and is composed of a magnetoresistance
effect element capable of detecting the direction and intensity of
the external magnetic field on the basis of the direction of the
magnetization of the fixed magnetic layer and the direction of the
magnetization of the free magnetic layer; and the detector detects
an intensity change of the magnetization in one direction output
from the magnet and obtains a first open detection output when the
rotation unit is rotated at a predetermined angle from the closure
posture to the display posture, and the detector detects an
intensity change of the magnetization in the other direction output
from the magnet and obtains a second open detection output when the
rotation unit is further rotated toward the display posture after
the first open detection output is obtained.
For example, when the rotation unit is rotated at an angle above
150 degrees from the closure posture, the second open detection
output may be obtained from the detector.
In the electronic device including the rotation unit according to
the embodiment of the present invention, the detection state of the
rotation unit can be detected by using the magnet and the detector.
By using the detector capable of detecting the direction of the
magnet field and the intensity of the magnet field, on the basis of
the one detector, it is possible to detect the detection state of
the rotation unit can be detected at the two angles. In addition,
as the detector is the non-contact type detection means, the
possibility that a failure is generated is small even when the
detector is used for a long period of time.
For example, according to an embodiment of the present invention,
when the first open detection output is obtained as the rotation
unit is rotated from the closure posture to the display posture, a
display of the display unit may be turned ON, and when the second
open detection output is obtained, a display content of the display
unit may be switched.
The switching of the display content herein means, for example, a
switching from a display of a still image to the display of a
video, a switching of a display language, and the like.
Alternatively, according to an embodiment of the present invention,
when the first open detection output is obtained as the rotation
unit is rotated from the closure posture to the display posture, a
display of the display unit may be turned ON, and when the second
open detection output is obtained, a content displayed on the
display unit may be turned upside down to be displayed.
In this manner, when the display content of the display unit is
turned upside down, by rotating the rotation unit up to an angle
close to 180 degrees or above, it is possible to present the
display content to a facing person, which is effective for a
setting of so-called presentation mode.
According to an embodiment of the present invention, an angle and a
direction of the magnet and the detector are preferably set to have
a rotation angle of the rotation unit up to a rotation limit
position of the display posture is reached after the second open
detection output is obtained, smaller than a rotation angle of the
rotation unit from the closure posture up to an angle at which the
first open detection output is obtained.
With the above-described configuration, the following configuration
can be adopted. When the rotation unit is rotated somewhat largely
from the closure posture and the display unit is located to be seen
by eyes, the display unit is turned ON, and furthermore, only when
the rotation unit is rotated largely, the display is switched.
Furthermore, according to an embodiment of the present invention,
when the rotation unit is rotated at a predetermined angle from a
rotation limit position of the display posture to the closure
posture, a second closure detection output may be obtained, and
when the rotation unit is rotated at a predetermined angle toward
the closure posture after the second closure detection output is
obtained, a first closure detection output may be obtained.
In this case, a rotation angle of the rotation unit from the
rotation limit position up to an angle at which the second closure
detection output is obtained is preferably larger than a rotation
angle of the rotation unit up to the rotation limit position after
the second closure detection output is obtained.
In this case, for example, when the second closure detection output
is obtained as the rotation unit is rotated from the rotation limit
position toward the closure posture, the display content of the
display unit may be returned to an original state.
Also, according to an embodiment of the present invention, a
rotation angle of the rotation unit toward the closure posture
after the first closure detection output is obtained is preferably
smaller than a rotation angle of the rotation unit from the closure
posture up to an angle at which the first closure detection output
is obtained.
In this case, for example, when the first closure detection output
is obtained as the rotation unit is rotated toward the closure
posture, the display of the display unit may be turned OFF.
Furthermore, according to an embodiment of the present invention,
the detector may include a detection element adapted to utilize a
magnetoresistance effect.
According to the embodiment of the present invention, by using the
non-contact and non-sliding type detection means, it is possible to
detect, at a plurality of positions, the rotation posture of the
rotation unit having the display unit. For that reason, it is
possible to perform the setting of the display state in accordance
with the rotation angle of the rotation unit. In addition, it is
also possible to perform the setting of the timing at which the
detection output is obtained and the rotation angle of the rotation
unit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an electronic device according to a
first embodiment of the present invention;
FIG. 2 is a side view of the electronic device according to the
first embodiment of the present invention;
FIG. 3 is a side view of an electronic device according to a
modified example of the first embodiment;
FIG. 4 is an explanatory diagram for describing a relative
positional relation between a magnet and a detector in the
electronic device according to the first embodiment and the
modified example of the first embodiment;
FIG. 5 is a line diagram of a relation between a rotation angle of
a rotation unit and an output from the detector in the electronic
device according to the first embodiment and the modified example
of the first embodiment;
FIG. 6 is a side view of an electronic device according to a second
embodiment of the present invention;
FIG. 7 is a line diagram of a relation between the rotation angle
of the rotation unit and the output from the detector in the
electronic device according to the second embodiment;
FIG. 8 is a side view of an electronic device according to a third
embodiment of the present invention;
FIG. 9 is a side view of an electronic device according to a fourth
embodiment of the present invention;
FIG. 10 is a side view of an electronic device according to a fifth
embodiment of the present invention;
FIG. 11A is a plan view of a structure of a magnetoresistance
effect element;
FIG. 11B is an explanatory diagram for describing a magnetization
direction of a fixed magnetic layer of the magnetoresistance effect
element and a direction of a bias magnetic field;
FIG. 12 is a cross-sectional view of an element part of the
magnetoresistance effect element;
FIG. 13 is a circuit diagram of the detector;
FIG. 14 is a line diagram of an output characteristic obtained from
the detector;
FIG. 15 is a circuit diagram of a detector according to another
embodiment of the present invention;
FIG. 16 is a line diagram of an output characteristic obtained from
a detector according to another embodiment of the present
invention; and
FIG. 17 is a line diagram of an output characteristic obtained from
a detector according to another embodiment of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a perspective view of an electronic device 1 according to
a first embodiment of the present invention, FIG. 2 is a side view
of the electronic device 1, and FIG. 3 is a side view of an
electronic device 101 according to a modified example of the first
embodiment.
The electronic device 1 illustrated in FIG. 1 is a note-type
personal computer and includes a device main body unit 2 and a
rotation unit 3. A casing of the device main body unit 2 contains a
circuit board to which electric components constituting a CPU or a
memory are mounted. A top face of the device main body unit 2 is an
operation face 2a. On the operation face 2a, a keyboard input
apparatus 4 and a capacitance flat-type input apparatus 5 are
provided.
On a display face 3a of the rotation unit 3, a screen of a display
unit 7 such as a liquid crystal panel. The rotation unit 3 is
freely rotatably mounted to the device main body unit 2 about a
rotation supporting point 6a or 6b illustrated in FIGS. 2 and 3. As
illustrated in FIGS. 2 and 3, the rotation unit 3 can set a closure
posture (a) in which while facing the operation face 2a of the
device main body unit 2, the display face 3a of the display unit 7
is overlapped on the operation face 2a with almost no gap. In
addition, the rotation unit 3 sets a display posture as the display
face 3a is rotated to a position away from the operation face 2a of
the device main body unit 2. FIG. 1 illustrates a display posture
(b) in which the display face 3a of the rotation unit 3 is
substantially orthogonal to the operation face 2a of the device
main body unit 2. As illustrated in broken lines in FIGS. 1 to 3,
the rotation unit 3 can be rotated up to a rotation limit position
(c) where the display face 3a faces right above. The rotation angle
of the rotation unit 3 from the closure posture (a) to the rotation
limit position (c) is 180 degrees.
In order to detect the rotation angle of the rotation unit 3, the
rotation unit 3 is provided with a magnet 8 at a position in the
vicinity of the rotation supporting point 6a or 6b, and the device
main body unit 2 is provided with a detector 10. As illustrated in
FIGS. 2 and 3, the magnet 8 is set in such a manner that the north
pole faces a Y1 side which is an upper side in the thickness
direction of the device main body unit 2 and the south pole faces a
Y2 side which is a lower side in the thickness direction of the
device main body unit 2 when the rotation unit 3 is in the closure
posture (a).
By utilizing a magnetoresistance effect, the detector 10 can detect
the direction of the magnetic field and the intensity of the
magnetic field, detect a magnetic field component in the Y1
direction which is the thickness direction of the device main body
unit 2 and a magnetic field component in the Y2 direction in
distinction from each other, and also detect the magnetic field
intensity in the Y1 direction and the magnetic field intensity in
the Y2 direction.
The detector 10 is configured in the following manner.
The detector 10 is configured by using a magnetoresistance effect
element 20 having the structure illustrated in FIGS. 11A and 11B
and FIG. 12 and incorporating a circuit illustrated in FIG. 13.
As illustrated in FIG. 11A, a plurality of element parts 21 of the
magnetoresistance effect element 20 are provided and formed in
parallel with one another. The longitudinal direction of the
respective element parts 21 extends in a direction orthogonal to
the Y1-Y2 direction. The longitudinal direction of the respective
element parts 21 may be a direction parallel to a paper surface of
FIGS. 2 and 3 or may be a direction orthogonal to the paper
surface.
As illustrated in a cross-sectional view of FIG. 12, the respective
element parts 21 are a giant magnetoresistance effect element (GMR
element) formed by laminating in the stated order on a substrate,
an antiferromagnetic layer 23, a fixed magnetic layer 24, a
non-magnetic conductive layer 25, and a free magnetic layer 26 and
covering a front surface of the free magnetic layer 26 with a
protective layer 27.
The antiferromagnetic layer 23 is formed of an antiferromagnetic
material such as an Ir--Mn alloy (iridium-manganese alloy). The
fixed magnetic layer 24 is formed of a soft magnetic alloy such as
a Co--Fe alloy (a cobalt-iron alloy). The non-magnetic conductive
layer 25 is formed of Cu (copper) or the like. The free magnetic
layer 26 is formed of a soft magnetic alloy such as an Ni--Fe alloy
(nickel-iron alloy). The protective layer 27 is formed of Ta
(tantalum).
In the element parts 21, due to an antiferromagnetic coupling
between the antiferromagnetic layer 23 and the fixed magnetic layer
24, the direction of the magnetization of the fixed magnetic layer
24 is fixed. As illustrated in FIG. 11B, in the respective element
parts 21, the fixed direction (P direction) of the magnetization of
the fixed magnetic layer 24 is a direction orthogonal to the
respective element parts 21 extending in the left and right
direction. According to this embodiment, the fixed direction (P
direction) of the magnetization of the fixed magnetic layer 24 is
the Y1 direction.
As illustrated in FIG. 11A, two of each of the element parts 21 are
connected via connection electrodes 28 and 29, and furthermore, the
element parts 21 located at upper and lower end parts in the
drawing are connected with extraction electrodes 31 and 32.
Therefore, the respective element parts 21 are connected in series
to form a meander type pattern.
As illustrated in FIG. 11A, in the respective element parts 21, a
magnet 33 is provided on the right side and a magnet 34 is provided
on the left side, and the bias magnetic field is provided with
respect to the respective element parts 21 in the left side which
is the longitudinal direction. Therefore, when the external
magnetic field is not provided, the inside of the free magnetic
layer 26 is in a single domain condition in a bias direction (B
direction) which is the longitudinal direction. The bias direction
(B direction) and the fixed direction (P direction) of the
magnetization of the fixed magnetic layer 24 are orthogonal to each
other.
As illustrated in FIGS. 11A and 11B, the magnetoresistance effect
element 20 can distinctly the component of the magnetic field in
the Y1 direction which is orthogonal to the longitudinal direction
of the element parts 21 and the component of the magnetic field in
the Y2 direction. When the magnetoresistance effect element 20 is
provided with the component of the external magnetic field in the
Y1 direction, the direction of the magnetization in the free
magnetic layer 26 on which the bias magnetic field B affects faces
the same direction as the Y1 direction, that is, the fixed
direction (P direction) of the magnetization of the fixed magnetic
layer 24. At this time, the electric resistance of the
magnetoresistance effect element 20 is decreased. On the other
hand, when the magnetoresistance effect element 20 is provided with
the component of the external magnetic field in the Y2 direction,
the direction of the magnetization in the free magnetic layer 26 is
the Y2 direction, that is, a direction opposite to the fixed
direction (P direction) of the magnetization of the fixed magnetic
layer 24. At this time, the electric resistance of the
magnetoresistance effect element 20 is increased.
As illustrated in FIG. 13, in the detector 10, the
magnetoresistance effect element 20 and the fixed resistance
element 35 are connected in series, the magnetoresistance effect
element 20 and the fixed resistance element 35 connected in series
are provided with a series voltage Vcc. Then, an intermediate point
36 between the magnetoresistance effect element 20 and the fixed
resistance element 35 functions as an output part of a detection
output.
FIG. 14 illustrates a relation of the component and the intensity
of the external magnetic field which affects the magnetoresistance
effect element 20 in the Y1 direction as well as the component and
the intensity in the Y2 direction and the output voltage from the
intermediate point 36. The fixed resistance element 35 is formed of
the same material as the magnetoresistance effect element 20
illustrated, for example, in FIG. 12 in the same thickness, and
also the laminating order for the non-magnetic conductive layer 25
and the free magnetic layer 26 is changed, for example, so that the
electric resistance is not changed due to the external magnetic
field and also the fixed resistance element 35 has the same
temperature characteristic as that of the magnetoresistance effect
element 20. In addition, when the external magnetic field is not in
effect, in order that the detection output from the intermediate
point 36 is set as Vcc/2, the resistance value of the fixed
resistance element 35 is adjusted.
As illustrated in FIG. 14, the output voltage from the intermediate
point 36 is set as Vcc/2 when the external magnetic field is not in
effect. When the external magnetic field in the Y1 direction
affects the magnetoresistance effect element 20, the output voltage
from the intermediate point 36 is increased, and when the external
magnetic field in the Y2 direction affects the magnetoresistance
effect element 20, the output voltage from the intermediate point
36 is decreased.
Therefore, as illustrated in FIG. 14, by recognizing that the
output voltage from the intermediate point 36 is set as a
predetermined value V1, it is possible to detect that the size of
the external magnetic field in the Y1 direction becomes equal to or
larger than a predetermined value H1. Similarly, by recognizing
that the output voltage from the intermediate point 36 is set as a
predetermined value V2, it is possible to detect that the size of
the external magnetic field in the Y2 direction becomes equal to or
larger than a predetermined value H2.
The detector 10 illustrated in FIG. 13 uses one magnetoresistance
effect element 20, but as illustrated in FIG. 15, it is possible to
use a detector 110 composed of a circuit using two
magnetoresistance effect elements 20A and 20B. The
magnetoresistance effect elements 20A and 20B used in the detector
110 are the same as the magnetoresistance effect element 20
illustrated in FIGS. 11A and 11B and FIG. 12. Alternatively, it is
also possible to use the detector which does not include the
magnets 33 and 34.
In the one magnetoresistance effect element 20A, the direction (P
direction) of the fixed magnetization of the fixed magnetic layer
24 faces the Y1 direction, but in the other magnetoresistance
effect element 20B, the direction (P direction) of the fixed
magnetization of the fixed magnetic layer 24 faces the Y2
direction. That is, the magnetoresistance effect element 20A and
the magnetoresistance effect element 20B are elements having the
same characteristic, but the arrangement directions are mutually
opposite with respect to the Y1 direction and the Y2 direction.
As illustrated in FIG. 15, in the detector 110, the
magnetoresistance effect element 20A and a fixed resistance element
35A are connected in series. In addition, a fixed resistance
element 35B and the magnetoresistance effect element 20B are
connected in series. Then, by way of a switch 39, with respect to
the magnetoresistance effect element 20A and the fixed resistance
element 35A, or with respect to the fixed resistance element 35B
and the magnetoresistance effect element 20B, a direct-current
power source voltage Vcc is alternately applied. In addition, by
way of a switch 38 operating in synchronism with the switch 39, an
intermediate point 36A and an intermediate point 36B is alternately
selected. The electric resistance of the fixed resistance element
35A is equal to that of the fixed resistance element 35B.
FIG. 16 illustrates the direction and the magnitude of the external
magnetic field when the magnetoresistance effect element 20A and
the fixed resistance element 35A are applied with the
direct-current voltage and a variation character of the voltage at
the intermediate point 36A. In addition, FIG. 17 illustrates the
direction and the magnitude of the external magnetic field when the
fixed resistance element 35B and the magnetoresistance effect
element 20B are applied with the direct-current voltage and a
variation character of the voltage at the intermediate point
36B.
As illustrated in FIG. 15, in the detector 110, reference
electrodes 37A and 37B to which the power source voltage Vcc is
applied are provided. A reference voltage at an intermediate point
between the reference electrode 37A and the reference electrode 37B
is set as Vcc/2. By way of a switching timing of the switch 39 and
a switching timing of the switch 38, a + terminal of a comparator
40 is alternately applied with the voltage at the intermediate
point 36A and the voltage at the intermediate point 36B. In
addition, a - terminal of the comparator 40 is applied with the
reference voltage Vcc/2.
A control unit (not shown) is adapted to monitor the output from
the comparator 40 when the output voltage from the intermediate
point 36A is supplied to the comparator 40 through the switching of
the switch 38 and the switch 39. When the output becomes +, it is
possible to determined that the size of the external magnetic field
in the Y1 direction becomes equal to or larger than Ha. In
addition, the control unit is adapted to monitor the output from
the comparator 40 when the output voltage from the intermediate
point 36B is supplied to the comparator 40. When the output becomes
-, it is possible to determined that the size of the magnetic field
in the Y2 direction becomes equal to or larger than Hb.
In the electronic device 1 illustrated in FIGS. 1 and 2 and the
electronic device 101 illustrated in FIG. 3, the magnetic field
generated from the magnet 8 which rotates with the rotation unit 3
is detected by the detector 10 (or the detector 110).
In the electronic device 1 illustrated in FIG. 2 and the electronic
device 101 illustrated in FIG. 3, when the rotation unit 3 is in
the closure posture (a), the cubic shaped magnet 8 faces
perpendicularly, in which the N pole faces upward, and the S pole
faces downward. In FIGS. 2 and 3, the positional relations between
the magnet 8 and the detector 10, and the rotation supporting
points 6a and 6b in the electronic device 1 or the electronic
device 101 are illustrated by using dimensions (mm).
In FIG. 4, the lines of magnetic force generated from the N pole
and the lines of magnetic force returning to the S pole are
illustrated. Ca and Cb represent isopiestic lines indicating that
the components of the intensity in the Y1 direction have the same
value. According to the embodiment of FIG. 4, the magnetic field
intensity in the Y1 direction is approximately 3 mT on the
isopiestic lines Ca and Cb.
In FIG. 4, 1A represents a relative rotation trajectory of the
detector 10 with respect to the position of the rotation supporting
point 6a of the rotation unit 3 in the electronic device 1
illustrated in FIG. 2 and the magnet 8. Similarly, 101 A represents
a relative rotation trajectory of the detector 10 with respect to
the position of the rotation supporting point 6b of the rotation
unit 3 in the electronic device 101 illustrated in FIG. 3 and the
magnet 8. The detector 10 moves on the rotation trajectory 1A and
the rotation trajectory 101A. The position of the detector 10 in
the closure posture is represented by (a) and position in the
rotation limit posture of the detector 10 after the rotation at 180
degrees is represented by (c).
In FIG. 5, 1B represents a curve indicating a relation between the
rotation angle of the rotation unit 3 and the magnetic
field-intensity detected by the detector 10 in the electronic
device 1, and 101B represents a curve indicating represents a curve
indicating the rotation angle of the rotation unit 3 and the
magnetic field intensity detected by the detector 10 in the
electronic device 101. As the direction of the magnetic field
affecting the detector 10 is changed while the rotation unit 3 is
rotated from the closure posture (a) at 180 degrees up to the
rotation limit position (c), the vertical axis of FIG. 5 shows that
the magnetic field has the polar characters of + and -.
The detector 10 has the output characteristic equivalent to that of
FIG. 14. In the control unit, four thresholds are set in the
detector 10. Thresholds +Va and -Va shown in FIG. 5 are set so as
to detect that the absolute values of the magnetic field
intensities are both set as 2.5 mT. In addition, thresholds +Vb and
-Vb are set so as to detect that the absolute values of the
magnetic field intensities are both set as 1.5 mT.
In the electronic device 1 illustrated in FIG. 2 and the electronic
device 101 illustrated in FIG. 3, when the rotation unit 3 is
rotated at a predetermined angle from the closure posture (a) to
the rotation limit position (c), the detection output from the
detector 10 (output voltage) is lower than the threshold +Vb. The
detection output at this time is a first open detection output.
When the rotation unit 3 is further rotated, immediately before
reaching the rotation limit position (c), the detection output from
the detector 10 exceeds the threshold -Va. The detection output at
this time is a second open detection output.
Next, when the rotation unit 3 is rotated from the rotation limit
position (c) to the closure posture (a), the detection output from
the detector 10 passes the threshold -Vb. The detection output at
this time is a second closure detection output. When the rotation
unit 3 is further rotated toward the closure posture (a), the
detection output from the detector 10 passes the threshold +Va. The
detection output at this time is the first closure detection
output.
In the detector 10 used according to this embodiment, the absolute
values of the threshold +Va and the threshold -Va are equal to each
other, and the absolute values of the threshold +Vb and the
threshold -Vb are equal to each other. The characteristics in the
detection are symmetry to each other at a border where the magnetic
field is zero. Therefore, a detector with a high general
versatility can be used as the detector 10. It should be noted that
the positions of the magnet 8 and the detector 10 are
asymmetrically arranged to the positions of the rotation supporting
points 6a and 6b, and thus, as illustrated in FIG. 5, in both the
electronic device 1 and the electronic device 101, the position of
the rotation unit 3 when the first open detection output (+Vb) is
obtained and the position of the rotation unit 3 when the second
open detection output (-Va) is obtained can be set as bilaterally
asymmetric angle postures with respect to the orthogonal direction.
In addition, the position of the rotation unit 3 when the second
closure detection output (-Vb) is obtained and the position of the
rotation unit 3 when the first closure detection output (+Va) is
obtained can be set as bilaterally asymmetric with respect to the
orthogonal direction.
In the electronic device 1 illustrated in FIG. 2, the rotation
angle from the closure posture (a) until the first open detection
output (+Vb) is obtained as the rotation unit 3 is rotated from the
closure posture (a) to the open posture is 37 degrees. Furthermore,
the rotation angle from the closure posture (a) until the second
open detection output (-Va) is obtained from the closure posture
(a) is 178 degrees. In addition, in a case where the rotation unit
3 is rotated from the rotation limit position (c) to the closure
posture (a), the opening angle of the rotation unit 3 from the
closure posture (a) when the second closure detection output (-Vb)
is obtained is 161 degrees. Furthermore, the opening angle of the
rotation unit 3 from the closure posture (a) when the first closure
detection output (+Va) is obtained is 22 degrees.
In the electronic device 101 illustrated in FIG. 3, the rotation
angle from the closure posture (a) until the first open detection
output (+Vb) is obtained as the rotation unit 3 is rotated from the
closure posture (a) to the open posture is 60 degrees. Furthermore,
the rotation angle from the closure posture (a) until the second
open detection output (-Va) is obtained is 177 degrees. In
addition, in a case where the rotation unit 3 is rotated from the
rotation limit position (c) to the closure posture (a), the opening
angle of the rotation unit 3 from the closure posture (a) when the
second closure detection output (-Vb) is obtained is 164 degrees.
Furthermore, the opening angle of the rotation unit 3 from the
closure posture (a) when the first closure detection output (+Va)
is obtained is 38.5 degrees.
As described above, when the rotation unit 3 is rotated from the
closure posture (a), the rotation angle from the closure posture
(a) until the first open detection output (+Vb) is obtained is
smaller than the rotation angle after the second open detection
output (-Va) is obtained until reaching the rotation limit position
(c). Furthermore, the rotation angle of the rotation unit 3 from
the closure posture (a) until the first closure detection output
(+Va) is obtained is smaller than the rotation angle of the
rotation unit 3 after the second open detection output (-Va) until
reaching the rotation limit position (c).
In the control unit, when the rotation unit 3 starts rotating from
the closure posture (a) and obtains the first open detection output
(+Vb), the display unit 7 is turned ON and information is displayed
on the display unit 7. Then, when the second open detection output
(-Va) is obtained, display of the screen on the display unit 7 is
inversed 180 degrees so that the display screen may be turned
upside down. With this configurations it is possible to use the
electronic device 1 in a so-called presentation mode in which the
display content on the display unit 7 is presented to a person on a
side facing an operator of the electronic device 1.
As compared with the rotation angle of the rotation unit 3 from the
closure posture (a) until the first open detection output (+Vb) is
obtained, the rotation angle of the rotation unit 3 after the
second open detection output (-Va) is obtained until reaching the
rotation limit position (c) is sufficiently small. In the
electronic device 1 illustrated in FIG. 2, the rotation angle of
the rotation unit 3 until the second open detection output (-Va) is
obtained is 178 degrees. In the electronic device 101 illustrated
in FIG. 3, the rotation angle of the rotation unit 3 until the
second open detection output (-Va) is obtained is 177 degrees.
In this manner, as the display state of the display unit 7 is
switched immediately before reaching the rotation limit position
(c) where the rotation angle of the rotation unit 3 becomes 180
degrees, when the display unit 7 faces the operator who is facing
the device main body unit 2, it is possible to prevent
unintentional switching of the display content of the display unit
7.
In addition, in a case where when the rotation unit 3 at the
rotation limit position (c) is rotated toward the closure posture
(a), when the second closure detection output (-Vb) is obtained,
the display content of the display unit 7 is returned to the
original state. That is, the display content switched to be turned
upside down is returned to the original state.
When the rotation unit 3 is rotated from the rotation limit
position (c) toward the closure posture (a), the rotation angle
from the rotation limit position (c) until the second closure
detection output (-Vb) is obtained is larger than the rotation
angle after the second open detection output (-Va) is obtained
until reaching the rotation limit position (c). Therefore, when the
rotation unit 3 is rotated toward the rotation limit position (c),
the display content of the display unit 7 is switched to be turned
upside down immediately before reaching the rotation limit position
(c). Then, when the rotation unit 3 is returned from the rotation
limit position (c), the display content of the display unit 7 is
not returned to the original state unless the rotation unit 3 is
rotated at a certain level of angle. In the electronic device 1
illustrated in FIG. 2, the rotation angle from the rotation limit
position (c) until the second closure detection output (-Vb) is
obtained is 19 degrees, and in the electronic device 101
illustrated in FIG. 3, the rotation angle is 16 degrees.
With the above-described configuration, after the display content
of the display unit 7 is switched to be turned upside down, even
when the rotation unit 3 is slightly moved, it is possible to
prevent the display content from being returned to the original
state. Therefore, while the display content of the display unit 7
is switched and the presentation is being performed, it is possible
to prevent the unintentional switching of the display content of
the display unit 7.
In addition, in a case where the rotation unit 3 is rotated toward
the closure posture (a), when the first closure detection output
(+Va) is obtained, the display of the display unit 7 is turned OFF.
As compared with the rotation angle of the rotation unit 3 until
the first open detection output (+Vb) is obtained to turn ON the
display unit 7 while the rotation unit 3 is rotated from the
closure posture (a), the rotation angle of the rotation unit 3
after the first closure detection output (+Va) is obtained to turn
OFF the display unit 7 until reaching the closure posture (a) is
small.
In a case where the rotation unit 3 is rotated from the closure
posture (a), as the display unit 7 is turned ON only after the
rotation unit 3 is rotated largely to some extent, it is possible
to prevent waste of the electric power while the rotation unit 3 is
slightly moved and the display unit 7 is unintentionally turned ON.
On the other hand, after the display unit 7 is turned ON, unless
the rotation unit 3 is rotated to a position in the vicinity of the
closure posture (a), the display unit 7 is not turned OFF.
Therefore, while the information is displayed on the display unit
7, even when the rotation unit 3 is slightly rotated, it is
possible to prevent the display unit 7 from being turned OFF.
In addition, in the electronic device 1 illustrated in FIG. 2 and
the electronic device 101 illustrated in FIG. 3, the magnet 8 is
arranged at a position away from the rotation supporting points 6a
and 6b and also on the center side of the rotation unit 3 as
compared with the rotation supporting points 6a and 6b, and
therefore the arrangement position of the magnet 8 is easily
selected.
FIG. 6 illustrates an electronic device 201 according to a second
embodiment of the present invention.
In the electronic device 201, the rotation unit 3 is provided with
the magnet 8, and inside the device main body unit 2, the detector
10 is arranged. The magnet 8 is provided at a position closer to
the center side of the rotation unit 3 than a rotation supporting
point 6c. In addition, the magnet 8 is arranged at 45 degrees with
respect to the X direction and the Y direction at a tilt. When the
rotation unit 3 is in the closure posture (a), the north pole side
faces obliquely downward, and the south pole side faces obliquely
upward. In the detector 10 arranged inside the device main body
unit 2, the longitudinal direction of the element parts 21
illustrated in FIG. 11A faces in a direction orthogonal to the
paper surface, and the direction in which the plurality of element
parts 21 are arranged is the X direction. Therefore, the detector
10 can detect the component in the X direction of the magnetic
field generated from the magnet 8. In addition, the positional
relation of the rotation supporting point 6c and the magnet 8 and
the detector 10 is as indicated by the dimensions shown in FIG.
6.
FIG. 7 illustrates a relation of the angle at which the rotation
unit 3 is rotated from the closure posture (a) up to the rotation
limit position (c) and the magnetic field intensity in the X
direction detected by the detector 10.
The threshold for obtaining the first open detection output is -Vb.
The rotation angle of the rotation unit 3 until the first open
detection output (+Vb) is obtained from the closure posture (a) is
36 degrees. The threshold for obtaining the second open detection
output is +Va. The rotation angle of the rotation unit 3 until the
second open detection output (+Va) is obtained from the closure
posture (a) is 178 degrees.
The threshold for obtaining the second closure detection output is
+Vb. The rotation angle of the rotation unit 3 when the second
closure detection output is obtained from the closure posture (a)
is 158 degrees. The threshold for obtaining the first closure
detection output is -Va. The rotation angle of the rotation unit 3
when the first closure detection output is obtained from the
closure posture (a) is 21 degrees.
Therefore, the timings at which the display unit 7 is turned ON and
OFF and the timing at which the display content of the display unit
7 is switched can be set similarly to the electronic device 1
illustrated in FIG. 2 and the electronic device 101 illustrated in
FIG. 3.
FIG. 8 illustrates an electronic device 301 according to a third
embodiment of the present invention.
In the electronic device 301, a rotation supporting point 6d of the
rotation unit 3 is located in a back side as compared with the end
part of the device main body unit 2. In the rotation unit 3, two
magnets 8a and 8b are provided. the magnet 8a and the magnet 8b are
separately arranged on the right side and the left side at
positions away from the rotation supporting point 6d while
sandwiching the rotation supporting point 6d. The face of the
magnet 8a facing the right side is the north pole. The face of the
magnet 8b facing the left side is the south pole. In the device
main body unit 2, the detector 10 is provided. The direction of the
magnetic field detected by the detector 10 is the X direction. The
arrangement positions for the magnets 8a and 8b with respect to the
rotation supporting point 6d and the arrangement position for the
detector 10 are as the dimensions shown in FIG. 8.
In the detector 10, four thresholds are set. As illustrated in FIG.
8, when the rotation unit 3 is in the closure posture (a), the
magnet 8a and the magnet 8b are positioned on an upper side than
the rotation supporting point 6d, and the detector 10 is positioned
at the same height as the rotation supporting point 6d. As a
result, the rotation angle from the closure posture (a) when the
first open detection output is obtained as the rotation unit 3
starts rotating from the closure posture (a) is 26 degrees. The
rotation angle from the closure posture (a) when the second open
detection output is obtained is 167 degrees. It should be noted
that the rotation angle up to the rotation limit position (c) is
180 degrees.
In addition, the opening angle from the closure posture (a) of the
rotation unit 3 when the second closure detection output is
obtained is 154 degrees. The opening angle from the closure posture
(a) of the rotation unit 3 when the first closure detection output
is obtained is 13 degrees.
FIG. 9 illustrates an electronic device 401 according to a fourth
embodiment of the present invention.
In the electronic device 401, the rotation unit 3 is provided with
the detector 10, and the device main body unit 2 is provided with a
magnet 8c and a magnet 8d. When the rotation unit 3 is in the
closure posture (a), the detection direction of the magnetic field
of the detector 10 is the X direction. In addition, the rotation
unit 3 is in the closure posture (a), the detector 10 does not
exist at the same height as a rotation supporting point 6e, and the
detector 10 is located on a closer side to the device main body
unit 2 as compared with the rotation supporting point 6e. The
magnet 8c and the magnet 8d are arranged at position away from the
position of the rotation supporting point 6e at an equal distance
on the left and right sides.
As illustrated in FIG. 9, when the rotation unit 3 is in the
closure posture (a), the detector 10 is positioned on a lower side
of the rotation supporting point 6e. The rotation angles for
obtaining the first open detection output and the second open
detection output and the rotation angles for obtaining the second
closure detection output and the first closure detection output can
be set similarly to the electronic devices 1, 101, 201, and 301
according to the above-described respective embodiments.
FIG. 10 illustrates an electronic device 501 according to a fifth
embodiment of the present invention.
According to this embodiment, in the rotation unit 3, the magnet 8
is positions on a rotation central line of a rotation supporting
point 6f. In the device main body unit 2, the detector 10 is
positioned immediately below the rotation supporting point 6f. The
direction of the magnetic field detected by the detector 10 is the
X direction.
In the electronic device 501 illustrated in FIG. 10, the rotation
angle from the closure posture (a) until the first open detection
output is obtained is the same as the rotation angle after the
second open detection output is obtained until reaching the
rotation limit position (c).
* * * * *